Mechanical pencil



July l1, 1950 A. scHwElTzER '2,514,610

MECHANICAL PENCIL,

Filed June 4, 1946 -2-..-ii-----:.:iasiHWWH Patented July 11, 1950MECHANICAL PENCIL Arnold Schweitzer, Geneva, Switzerland, assignor toFabrique Suisse de Crayons Caran dAche S. A., Geneva, Switzerland, a.corporation of Switzerland Application J une 4, 1946, Serial No. 674,226In Switzerland March 13, 1946 The present invention relates tomechanical pencil and is an improvement over a type of pencil comprisingan outer shell having at one end a conical seat, a lead guiding tubecarrying at one end jaws clamping the lead when in said seat, acontrolled spring urging the tube inwardly and the jaws to their seat,auxiliary jaws normally urged to lead clamping position through openingsin the tube, but retracted from lead clamping position by a central camduring the spring-urged back stroke of the tube.

This otherwise satisfactory pencil structure has the. disadvantages of ahigh production cost, of the complicated shape of the auxiliary jaws andof the diiliculty of accurately positioning the cam retracting theauxiliary jaws.

These and other disadvantages are overcome by the embodiment of thepresent invention.

The present invention has for its object a leadholder of the type citedabove and which tends to avoid the inconveniences mentioned owing to thefact that a stationary clamping organ is provided in the shell, the armsof the auxiliary jaws having a portion cooperating with said stationaryclamping organ in such a manner as to cause the elastic application ofsaid auxiliary jaws on the lead engaged in said leads guiding tube whensaid control member is actuated against the action of said restoringspring, and so as to maintain said auxiliary jaws and said lead in afixed position with respect to said shell while said leads guiding tubeperforms a portion of its back stroke, this back stroke being caused bysaid restoring spring when said control member is released by theoperator, whereby the automatic forwarding of the lead between theclamping jaws is produced.

The annexed drawing shows diagrammatically and by way of example twoforms of construction of the lead-holder.

Fig. 1 is a view of an axial section of a form of construction with someportions removed, the lead being clamped in its position of servicebetween the clamping jaws.

Fig. 2 is a similar view, with the clampingr jaws in a forwardedposition.

Fig. 3 is a similar view of a second form of construction, the leadbeing in a forwarded position between the clamping jaws, these latterbeing represented in an intermediate position taken during their backstroke.

The lead-holder represented on the drawing by way of example comprisesafter the fashion of other known lead-holders:

An outer shell I, of general cylindrical shape, with a pointed end inwhich a conical seat 2 is .A prises a member sliding freely along theleads 4 Claims. (Cl. 1Z0-17) provided. A leads guiding tube 3 carryingat one of its ends clamping jaws 4 emerging from this pointedv end ofthe shell, is subjected to the action of a restoring spring 5 tending tomaintain jaws 4 applied on conical seat 2. This leads guiding tube bearsat its other end a leadsv magazine AI5 covered by a control member 1emerging from the end of shell I opposite to the clamping jaws 4.

The lead feeding device of the invention comguiding tube 3 between twoextreme positions determined by two abutments I0 and ll. This slidingmember is provided with twoauxiliary jaws I2 traversing the'wall of theleads guiding tube 3 through longitudinal openings I3. These auxiliaryjaws are borne by elastic arms 14 rigidly connected at one end to anannular portion` l5 engaged over the leads guiding tube 3. Arms I4 havea shoulder I5 cooperating, when the control member 1 is actuated, with aclamping organ constituted by a shoulder I1 of shell I, and on whichrests the restoring spring 5 of the leads guiding tube. The portionofthe shell I located between this shoulder I1 and the pointed end i hasvan axial vhole I9 of a smaller diameter than the bore 20 of the portionof the shell extending from this shoulder to the'other end. Y

In Fig. 1, the elements of the lead-holder are represented in theposition of rest, the lead 8 being maintained in its position of serviceby clamping jaws 4. These latter are applied on the lead owing to theaction of the restoring spring 5 tending to jamb the jaws in conicalseat 2.A y f l When the user desires to cause the forwarding of the leadbetween the clamping jaws, it is sufli-4v cient for him to exert anaxial pressure on the control member 'I against the action of the re.-storing spring 5 in order to bring -the various members of thelead-holder into the position rep- S resented in Fig. 2.

Control member 'I drives with it leads magazine 6 leads guiding tubev 3and clamping jaws 4, all these parts being rigidly connected one to theother. During this movement, abutment II constituted by the frontal faceof magazine 6 comes in contact with a rear face IB of the ring portionI5 of the sliding member and drives the latter for the latter portion ofthe forward stroke of the control member 1.

During the movement of the sliding member, shoulders I6 of elastic armsI4 slide over shoulder Il of the shell and enter hole I9 of smallerdiameter, which causes the clamping of aux- ,iliary jaws I2 upon thelead 8 (Fig. 2). y

' As previously indicated, the' jaws 4 cooperate ber l.

they are drawn into the socket by the-spring..F

5, but when the control member.` I ismovedto When the lead is in writingposition.

push the tube 3 downwardlyth'ejaws.are .moved out of the seat 2 but thejawss4l @still clamp thelead with sucient friction to prevent the leadfrom falling from between s'aid jaws. As-`shown.

in Figure 2 the lead 8 has been'givemadisplace ment of the samemagnitude of the control memsocket as the displacement stroke of thetube 3 proceeds# the vauxiliary` jaws 2. which have-,been applied/.byvirtue of the.-shoulder. I 6 vof vthermembers L14: ridingvovertheshoulders ill; the lead -8 willl be i pushedf through the jaws-,1l aAsuflicient amountA toy provide the-additional: length of lead :IcrwritingV 'purposess Whenvzthe'user'freleasesf'control member "I,restoring-spring.` =causes--a: back.` motion of leads guiding tube 3 andclamping jaws 4. Neverthe@ lesszzthesliding member'. the elastic armsI4f'of which are brought.v together in the inside pinhole I94 of f'shell:.I is; maintained'stationarywith respect to. thesshell byithefrictionofarms I-4'and thefwalls fof." thefholef;I I9.; Auxiliary,A jaws-1 I2maintain; thus @the lead 1in:Y ai fixed position with respect to.:shelL'I` andstlexfjawsz-g4 can-:slide over the lead! The-free stroke.of'thefsliding .member iis limited by in on'edirecti'onl theterminalfwalls'of the When the jaws 4 are moved out'of '-the.;

two# longitudinal slots.: I3, ,inzwhichf auxiliary andtakes theAslid'i'ngfnrenriber along fortheflatter portion Aof- 'the fbackwardmovement of l'the :leads guiding tube. This-movementof theA slidingmember causes the disengagement of the-'elastic arms I4 fromy the holeI9Iand fromthefsh'oulder I'If andtherefoie the =liberation yofilead8f-rom the auxiliaryjaws. Towards rthe end 'of-.the back stroke of theleads guiding ftube A3, 'clampingjaws 4 vfengaging' witl-conical seat2,2 become clamped on lead '8 "(Fig. 1) Tand maintain'same in its Aposi.tion of service:

From the above; it mayb'efseen, that thedescribed leads-holder,although-containing only al veryY small "number" of vrparts asy comparedwith known` leads-holders operates in" an.I absolutely safe' manner. n

Furthermore, no part or 1 constitutive imember. of this leads-holdernecessitates accuratezmae. chining; This peculiarity represents. a greattechnicaladvantage-*and ensures. a long service life--to thedescribedfleadseholder. Lastly, the assemblyfof` the latter isexceedingly easy and rapid-'iasit-does not necessitateany adjustment.

Furthermore, in the above described." leads' holder'thef elasticity of'arms I4 must be only sucientfto prevent a took high pressure from beingexerted by auxiliary:jaws I21on lead 8. This velastic characteristicdoes not require any special property of the jaw arm I4.. Further, thefrictions r'are much smallerzthan in known leadsholdersvso thatrestoringfspring 5Jdoes `notneed to be strong.

In: the form of"A construction represented? in 4 Fig. 3, a sleeve 22with an axial hole I9 is slipped in the bottom of axial hole 20 of outershell I. The edge of this sleeve is shaped into a collar forming theshoulder Il on which rests restoring spring. 5. Clamping jaws 4 arecarried by a tubularholder 23, the/end .of which v`is screwthreaded. Thefree end of the leads guiding tube 3 :is also provided with a screwthread. A screw threaded nipple 24 holds together holder 23 and leadsguiding tube 3.

From theeinspection of Fig. 3, it may be seen that ;thefassembly;of thedescribed leads-holder is Vvery'quickH and easy. Indeed, after thesleeve 22 has been'V placed in the outer shell I and the slidinggmemberhas been slipped over the leads guidinggtube'and the nipple 24 has beenscrewed to the free end of the latter, it is suicient to sli'prrestoringspring 5 over` the sliding member and to introduce the whole in theouter shell I. Bye exerting a pressure onthe -endof'the magazine-f6,"spring l-5 is maintained inV its compressed position andthe clampingjaws viv may be introduced through the pointed end of the Ashell andIscrewed :into nipple 24. After filling magazine-61 with'leadal and'placing over `it control 'membern "I theleads-jholder is ready foruse.4

One of Vthe'greaifadvantages of the described leads-holder` consistsinthe fact ithat the amplitude of the forwarding'movement'iof vtheleadisalways the same and 'equals the amplitudeof the vfreestrokeof thesliding member from. one tcV the `other of the twoabutrnents I0 'andII..

I claim:

l. In a propelling pencil .the.combination.com-` prising, an outer shellhavinga-.conical. seatin one end, a` lead.. guid.ing.tube.disposed. in,said shell, lead gripping` jaws. carried by the lower end of.the-tube.and...normally engaging said seat tormly holdthe. leadinwriting position, said jaws when projectedout of theseat being adaptedv.to-.clamp-.the-'lead less .firmly topermit its. movement between thejaws,` spring .means held at-one end kbysaid .shell a controlsmernber insaid.shell andl connected to..saidtubefandv eir-l gaged by said-springmeans andthereby urged to a position Vprojecting.:through the other endof said.shell,. means in, saidrv shell and-guided' by said-"tube and.engageable at itsY upper end. by said control` member land having at itslower endauxiliary lead engaging andfieeding jaws normally urgedtoleadreleasing position, elongated openings.A in said .tube providingsaid auxiliary j awsaccess to. theyleadand a path. ofi movementlengthwise of said tube, cam means in said shell engageable by saidauxiliary jaws after the out' wardf propulsion` ofsaid tube: by theinward movement of .thecontrol,memberand after the release of the leadby said vgripping jaws and upon continued :inward movement of y saidcontrol member, said camY meansurging said auxiliary jaws to leadrclamping.l position, whereby inward movement of said control member willpropeLsaidvtube-ain said shelli outwardlyk of said casing and disengageAsaidigripping jaws from said seat and thus :partially release ysaid jawsfrom' thezlead .and then move said means guided bysaid' tube and force.said auxiliary jaws into engagement with said cam means to cause same toclamp the lead:throughv said openingsand to Imove the'lead in said tubeoutwardly'through said `released gripping 'jaws and whereby upon releaseof said controlmember the ends-of said. openingsmove saidauxiliary'jawsand said means guidedfby saidrtubeiztosaf position inrwhich said'auxiliary jaw means are disengaged from said cam means.

2. In a propelling pencil, the combination according to claim 1 andwherein said shell is 'provided with shoulder means holding said springmeans and camming said auxiliary jaws upon continued inward movement ofsaid control member.

3. In a propelling pencil, the combination according to claim 1 andwherein a sleeve is dis- 10 posed within said shell for holding saidspring means and camming said auxiliary jaws upon continued inwardmovement of said control member.

4. In a propelling pencil, the combination, acl cording to claim 1 andwherein the means in said shell and guided by said tube is engageable atits upper end by said control member after initially stressing saidspring.

ARNOLD SCHWEITZER.

REFERENCES CITED The following references are of record in the ile ofthis patent:

UNITED STATES PATENTS Number Name Date 1,803,794 Deutsch May 5, 19312,078,433 Winter Apr. 27, 1937 FOREIGN PATENTS 5 Number Country Date219,430 Switzerland May 16, 1942-

